Photoshop really slow in opening files

I'm new to this forum and am having problems opening files with Photoshop. I'm trying to open, nothing else, a psd that's 139.6 MB, not too big. The problem is that Photoshop is taking forever just to open the file. What should I do to remedy this? After the file has finally opened, everything takes a long time to perform. Even if the help is just instructing me how to search for the help via previous posts, then that's fine. I'm working on a Dual 1 GHz PowerPC G4, 1 MB L3 cache, OS Version 10.4, and 1.5 GB DDR SDRAM. Thank you for your time.

There are many things that can casue this such as opening the file. SOme common fixes are

purge your cache
copy the file to your hard drive
run norton disk doctor or some disk utility
check that your ram is proerly installed
make sure your drive has plenty of free hard drive space
close unnecessary fonts
close all other open applications
create a new user in OSX and log in as that, then try to open the file